赣江外洲站近50年水沙变化规律

Variation of runoff and sediment load at Waizhou hydrologicstation in Ganjiang River in the last 50 years

基于赣江外洲站年径流量时间序列(1957—2008年)和年输沙量时间序列(1966—2008年),采用肯德尔秩次相关检验法、有序聚类分析和秩和检验法、小波分析法对赣江水沙变化规律进行分析.结果表明:年径流量时间序列趋势变化不明显,不存在显著跳跃点,当时间尺度为17时,存在以10～12 a为周期的丰枯变化.年输沙量时间序列下降趋势明显,在1984年和1998年附近发生跳跃,周期性变化可分为两段,1966—1986年间,在时间尺度为6时平均变化周期约为4 a,1986年后,在时间尺度为1时平均变化周期约为3.7 a.水土保持、人工采砂、万安水库拦沙等是影响赣江输沙量显著变化的主要因素.

The time series of runoff and sediment load at Waizhou 1957 to 2008 and from 1966--2008 is analyzed respectively with hydrologic station on the Ganjiang River from the methods of Mann-Kendall rank correlation test, sequential clustering analysis, rank-sum test and wavelet analysis. The results show that annual runoff has not an obvious trend and jumping point, and there are cycles of 10 - 12 years between wet years and dry year at the time scale of 17 years. However, annual sediment has a clear downward trend, there is sharp decline in 1984 and 1998, and the periodic change can be divided into two periods, there is an average cycle of 4 years in the time scale of 6 years from 1966 to 1986, and there is an average cycle of 3.7 years in the time scale of 1 year after 1986. Soil and water conservation, artificial sand mining, Wanan Reservoir sand blocking are the main reasons of the decrease of the annual sediment at Waizhou hydrologic station on the Ganjiang River.